Imazapyr
| 1 Trade name | Manufacturer | Form |
| ARSENAL 750 SG HERBICIDE | BASF AUSTRALIA LTD. | GR |
| ARSENAL HERBICIDE | BASF AUSTRALIA LTD. | AC |
| MACPHERSONS CHOPPER 750 SG HERBICIDE | RONIC INTERNATIONAL PTY LIMITED | SG |
| UNIMAZ 250 SL HERBICIDE | UNITED PHOSPHORUS LTD. | SL |
Rates quoted in HerbiGuide are for the 250g/L liquid forms. Multiply rates 0.33 if using the 750g/kg granular products.
2 PRICE:
3 ACTIVE INGREDIENTS: Imazapyr 250g/L or 750g/kg
As the isopropyl amine salt as an aqueous solution or granule.
4 CHEMICAL GROUP: B5 RELATED HERBICIDES:
| Broadstrike | Flumetsulam 800g/kg |
| Chlorsulfuron | Chlorsulfuron 750g/kg |
| Crusader | Pyroxulam 30g/L |
| Eclipse | Metosulam 100g/L |
| Eclipse | Metosulam 714g/kg |
| Ethoxysulfuron | Ethoxysulfuron 600g/kg |
| Express | Tribenuron methyl 750g/kg |
| Flame | Imazapic 240g/L |
| Harmony M | Metsulfuron 68g/kg + thifensulfuron 682g/kg |
| Imazapyr | Imazapyr 250g/L or 750g/kg |
| Intervix | Imazamox 33g/L + imazapyr 15g/L |
| Iodosulfuron 100 | Iodosulfuron 100g/kg |
| Iodosulfuron 50 | Iodosulfuron 50g/kg + mefenpyr |
| Lightning | Imazapyr 175g/L + imazethapyr 525g/L |
| Logran 750 | Triasulfuron 750g/kg |
| Londax | Bensulfuron 600g/kg |
| Mesosulfuron 30 | Mesosulfuron 30g/L |
| Metsulfuron-methyl | Metsulfuron 600g/kg |
| Monza | Sulfosulfuron 750g/kg |
| Muster | Ethametsulfuron methyl 750g/kg |
| OnDuty | Imazapic 525 + Imazapyr 175g/L |
| Raptor WG 700 | Imazamox 700 g/kg |
| Sempra | Halosulfuron 750g/kg |
| Spinnaker | Imazethapyr 700g/kg or 240g/L |
| Sulfometuron | Sulfometuron 750g/kg |
| Titus | Rimsulfuron 250g/kg |
| Trifloxysulfuron | Trifloxysulfuron 750g/kg |
6 GENERAL DESCRIPTION:
A residual, foliar and root absorbed herbicide that is non selective at high rates.
7 APPLICATION METHODS AND TIPS:
Best results when applied to actively growing plants and rain occurs a day or two after application.
To reduce foaming, add herbicide when the tank is full, then agitate thoroughly.
8 WEATHER:
Rainfast in 2 hours for post emergent applications. Rainfast immediately for pre emergent applications.
Frost effects: Poorer post emergent activity in frosty conditions.
Wind:
Inversions: Avoid application during low level inversions as excessive drift may occur.
Temperature:
Delta T and relative humidity: Avoid application when Delta T is greater than
9 ADJUVANTS:
Wetting agents: Not required.
Spray oils: Usually not required.
10 WATER QUALITY:
Hard water: Tolerates hard water.
Salty water:
Colloids:
pH:
Tank life: A few weeks.
11 COMPATIBILITY:
Trace elements.
Don't mix with bipyridyl herbicides such as diquat, paraquat or Spray.Seed because this reduces the uptake and translocation of imazapyr in post emergent situations. Pre emergent activity is not affected.
See HerbiGuide Compatibilities button.
12 EQUIPMENT:
Boom sprays:
Carrier volume: 50-200 L/ha water.
Nozzles: Flat fan.
Pressure: 150-400 kPa.
Droplet size: 150-400 micron.
High volume:
Carrier volume: 1000-4000 L/ha depending on vegetation density. Apply until wet but without runoff.
Aerial application:
Carrier volume: 30 L/ha.
13 SPRAYER DECONTAMINATION:
Clean Up:
Clean soon after spraying to reduce the risk of forming dried deposits that may be difficult to remove.
Remove filters and clean separately. Triple rinse with water or water plus 0.25% wetting agent and run through boom.
Decontamination:
Remove filters and clean separately.
Rinse with water and drain.
Quarter fill the tank with an alkali detergent (eg 500 mL or g of Drive, Dynamo, Omo, or Surf per 100 L water) and circulate for at least 15 minutes then run through boom. Rinse twice with water.
14 HERBICIDE RESISTANCE:
Tolerant plants are expected to occur and may dominate the weed population after repeated applications.
15 REPLANTING INTERVALS:
16 WITHHOLDING PERIODS:
| Crop | Type | Time |
| All | Grazing | Long |
| All | Harvest | Long |
Other products containing imazapic have grazing withholding periods of 4-6 weeks. At low rates, stock problems are not expected for these periods.
17 RE-ENTRY PERIOD:
Wear protective clothing if in contact with the crop before the spray has dried.
18 PROTECTIVE CLOTHING:
Overalls, boots and washable hat. Use gloves and face shield when handling the concentrate.
19 SOIL:
Soil texture:
Soil pH:
Soil organic matter:
Soil moisture at application: Best results if soil is moist.
20 MODE OF ACTION:
Group B imidazolinone group herbicide. Inhibits the AHAS/ALS (acetolactate synthase) enzyme. Translocates rapidly to the growing tips of roots and shoots inhibiting the production of essential amino acids and preventing new cell growth. Plants stop growing soon after application but symptoms may take over 30 days to show. New growth may be discoloured and distorted. Imazapyr may be released back into the soil after plant death and decay to provide pre emergence control of later germinating weeds. Higher rates give longer residual control.
Uptake and translocation:
Rapidly absorbed and translocated up and down the plant to the growing points.
Physiological effects:
Residual Life and Breakdown:
Half life in soil is 6 weeks to 2 years in temperate climates and less in tropical climates.
21 SELECTIVITY:
Crop tolerance:
Cotton, tobacco, tomatoes, flowers, vines and fruit trees are sensitive to imazapyr.
Varietal sensitivities:
Effect on Clover Species:
Damages clover.
Effect on Medic Species:
Damages medic.
Effect on Lucerne:
Damages lucerne
Effect on Native Plants:
Damages many young native plants at high rates. Some natives will tolerate low rates.
22 DISEASE AND INSECT EFFECTS:
23 PLANT SYMPTOMS:
Cessation of growth soon after spraying. Discolouration of foliage may occur 2-4 weeks after spraying and new growth may be distorted. It may take many weeks before plants wither and die. In some cases plants may remain stunted and unproductive.
SECONDARY EFFECTS:
24 TOXICITY:
Summary:
Low toxicity to mammals, birds, fish and insects.
Details:
Poison schedule: Not a scheduled poison. (S5 for Arsenal Express)
Mammalian toxicity:
Acute oral LD50: >5000 mg/kg (rat), [For comparison table salt is 3000 mg/kg] Low toxicity.
Acute dermal LD50: > mg/kg (rabbit).
Skin: May irritate the skin.
Eye: May irritate the eyes.
Vapour inhalation: LC50 > 5.1 mg/L air (rat).
Chronic oral toxicity: NOEL mg/kg for two years.
Not carcinogenic, mutagenic or teratogenic in animal studies (i.e. does not cause cancer or reproductive problems in animal tests).
Acceptable Daily Intake (ADI): 2.5 mg/kg/day.
NOEL 250 mg/kg/day.
Other Species:
Birds: Not toxic.
Fish: toxicity LC50 >100 mg/L. Not toxic.
Invertebrates: toxicity.
Bees: Not toxic.
Arthropods: toxicity.
Earthworms:
Algae:
Accumulation:
25 TOXICITY SYMPTOMS:
26 FIRST AID:
If SWALLOWED: Wash out mouth with water. Give a glass of water. Do NOT give anything by mouth to a semiconscious or unconscious patient. Do NOT induce vomiting. Place patient to prevent vomit entering lungs. If vomiting occurs give more water to drink to aid dilution.
If in EYES: Hold eyelids open and wash eyes with plenty of water for 5 minutes, remove contact lenses if present and wash for a further 10 minutes. See a doctor if symptoms persist.
If on SKIN: Remove contaminated clothing. Wash skin thoroughly with soap and water.
If INHALED: Remove patient to fresh air. See a doctor if symptoms persist.
Advice to doctor: Treat symptomatically.
Contact the Poisons Information Centre on 131126.
27 ENVIRONMENTAL FATE:
Half life in soil: 6 months to 2 years in temperate climates
Half life in water: days at pH5 and 35 C.
It has an EPA classification for soil mobility that ranges from
It has a leaching index of . (for comparison, trifluralin is 0-1 and chlorsulfuron is 25-30).
Ground water contamination:
Accumulation in milk and tissues:
pH stability:
Photolysis rate:
Hydrolysis half life:
Biodegradation rate:
Bioconcentration factor (BCF):
28 REGISTERED CROPS:
See HerbiGuide Species Solution tab.
29 REGISTERED WEEDS:
See HerbiGuide Species Solution tab.
30 REGULATION AND LEGAL:
UN number: None allocated.
CAS numbers: 81334-34-1
OPP Chemical Code:
Hazchem code: None allocated.
NOHSC classification: Non hazardous.
Land transport:
Dangerous goods class (ADG): Not a dangerous good.
Sea transport:
Proper shipping name:
International Maritime Dangerous Goods Code (IMDG):
Class:
Packaging group: None allocated.
EPG:
Risk phrases:
Safety phrases:
31 PROPERTIES:
Colour: Clear amber liquid or cream granules.
Odour: Faint amine odour.
Form: Liquid or granules
Chemical name:
Empirical formula:
IUPAC:
CAS: 81334-34-1
Water solubility: Soluble in water. mg/L at 25 C at pH
Oil solubility:
Octanol:Water ratio: LogPow = at 25 C at pH 5. (Partition coefficient = 0.11)
Soil organic carbon absorption coefficient (Koc):
Vapour Pressure: <0.013 mPa at 60 C.
Vapour density:
Dissociation constant: pKa
Melting point: C.
Boiling point: C.
Molecular weight:
Bulk density:
Specific gravity: 1.06-1.12
Viscosity: CPS.
pH: 6-7.3
Flammability: Non combustible.
Flashpoint: C.
Autoignition: C.
Corrosivity: Corrosive to mild steel and brass.
Shelf Life: years.
(When Stored under Ideal Conditions)
Stable under normal conditions.
Hazardous polymerisation in not possible.
The addition of a strong alkali such as caustic soda will cause release of
isopropylamine vapour which is moderately toxic, LD50 (oral, rat) is 820 mg/kg.
32 SPILLS:
Absorb spill with earth, sand, clay or absorbent material such as vermiculite.
Prevent spill from entering drains or waterways.
33 FIRE:
Extinguish with water spray, foam, carbon dioxide or dry agent.
Toxic fumes may be released in fire. Wear breathing apparatus or avoid smoke.
Product reacts with galvanized steel to produce hydrogen which may form an explosive gas mixture.
Prevent fire fighting water from entering drains and waterways.
34 COMMENTS:
35 REFERENCES:
Ashton, F.M. and Crafts, A.S. (1981) Mode of Action of Herbicides. (Wiley-Interscience publication).
Kearney, P.C. and Kaufman, D.D. (1976). Herbicides. Chemistry, degradation and mode of action. Vol 1 & 2.
Arsenal label (2007) MSDS Arsenal (May 2007). MSDS Arsenal Express (April 2009).
Acknowledgments:
Collated by HerbiGuide. For more information see www.herbiguide.com.au or phone 08 98444064.